1. Field of the Invention
The present invention relates to the cable drop wire terminal, in particular to a double-wall casing and terminal block housing. The invention particularly concerns a light weight, strong, unitary cable splice closure and aerial drop wire box as used in the electrical transmission and telecommunications industries.
2. Description of the Prior Art
There are a number of patents which illustrate aerial communication cable closures which have associated therewith a terminal box for connecting drop wires to selected wire pairs of the cable. Examples of these patents are U.S. Pat. Nos. 3,836,696; 4,390,744; 4,535,197; 4,536,611; 4,605,815; 4,647,715; and 4,694,118. Each of these closures have a closure and a drop wire box for connecting drop wires at the same location of a cable splice or where a cable is opened.
There are other drop wire boxes which are separate from the closure and are designed to hang from the closure or hang separately from the support strand. Examples of these are U.S. Pat. Nos. 4,414,426; 4,513,171; and 4,992,627.
Of the first group of patents, U.S. Pat. No. 3,836,696 discloses a single-piece molding of relatively rigid plastic material and it has a single door 26 mounted by an integral or living hinge 27. On this unit, opening the door exposes the terminal panel 30 which is a single piece I-beam shaped structure which is mounted in the housing 20. This structure has a lot of extra parts making it cumbersome to mount on the wire and heavy. U.S. Pat. No. 4,390,744 discloses an integral drop wire terminal and closure which comprises multiple structural pieces which are fitted on a support bracket 40 including clamp brackets 70 and 72 and mounting bar 42. A barrier wall 44 supports the terminal members and divides the cable conductor portion from the terminal compartment. As readily seen the closure is very complicated and includes a number of independent heavy support parts to hold the same on the support strand and on the cable. U.S. Pat No. 4,535,197, in FIGS. 8-11, illustrates a closure having a terminal area with a separate terminal lid. The invention is directed at a closure that is maintained secure and more impervious to rain water, ultra-violet light and insects. The patent says the closure 10 includes a hollow, flexible wall, tubular housing 18 with a pair of longitudinal mating edges 20 and 22 separated by longitudinal access slot. The embodiment of FIG. 8 includes a termination port 25 including a rectangular frame 24 formed about a rectangular opening in one side of the tubular housing 18 between ribs 30 and 30'. A rectangular lid hinged to the frame 24 closes the opening. U.S. Pat. No. 4,536,611 discloses a tubular frame similar to that of U.S. Pat. No. 4,535,197 but has a separate terminal block panel assembly 34 installed within a rectangular frame 24 with a separate lid 28. U.S. Pat. No. 4,605,815 discloses a two part 14a, 14b shell and the shells are held together by articulated bindings 30 and 31. The shell 14a has affixed to the exterior of its mid-portion a terminal block compartment 26 which is accessible through an upwardly pivotal door 28. This closure is designed to have separate areas such that unauthorized personnel cannot inadvertently disturb the wirework area but only leave the block compartment accessible through door 28. U.S. Pat. No. 4,647,715 discloses another closure by David O. Butler including a one-piece, hollow, box-like housing 16 with longitudinal interconnecting edges 22 and 24 which can be fastened to close the closure after the cable has passed through the slot. FIGS. 4-7 illustrate a separate terminal compartment 71 which is attached to one side of the housing 16 by bolts which extend through the housing. A terminal block is mounted within the compartment 71. A popular aerial closure is illustrated in U.S. Pat. No. 4,694,118, but this closure is a heavy structure formed of high impact plastic with a splicing housing and a terminal housing, affixed and disposed immediately below the splicing housing. The splicing housing has a hinged cover 36 and terminal housing has a cover 48. Each compartment has a top wall, back wall, opposite end walls and a bottom wall. This structure boarders on the separateness of the terminal block from the splice compartment, but they have openings through the congruent portions of the housing and block for the wires of the terminal block to pass.
The patents disclosing the separate termination housings do not have common areas or walls and are generally separately suspended from the support strand.
The prior art patents for combined closures and terminal blocks do not teach making such a structure by the blow molding process or how the blow molding can effectively be utilized to reduce the number of parts and provide the convenience of mounting and use afforded thereby. There is prior art concerning the blow molding of aerial closures and one patent is U.S. Pat. No. 4,810,829 which teaches the advantages of blow molding for closures to obtain a light strong closure. There is no teaching, however, of using the structure of this closure for a drop wire closure and combining the two to obtain the advantages and convenience that is available with the present invention.